Protective casing for a display screen and a method and tool for manufacturing such a casing

ABSTRACT

The invention proposes a protective casing ( 12 ) for an electronic appliance ( 10 ) of the type which has a shell ( 18 ) in which there is produced an opening ( 20 ) closed off by a body ( 22 ) made from transparent material with a general flat shape, of the type in which at least one internal peripheral annular fixing area ( 30 ) of the transparent body ( 22 ) is fixed to a facing area ( 32 ) of the periphery of the opening ( 20 ) by fixing and/or positioning means ( 34 ) with the interposing of a first decorative cladding ( 38 ) between the peripheral fixing area ( 30 ) of the transparent body ( 22 ) and the fixing and/or position means ( 34 ), characterized in that the peripheral fixing area ( 30 ) is inclined with respect to the overall plane of the transparent body ( 22 ). 
     The invention also proposes a method and tool for manufacturing such a casing.

The invention proposes a protective casing for an electronic appliance.

The invention proposes more particularly a protective casing for anelectronic appliance of the type which has a shell in which there isproduced an opening closed off by a body made from transparent materialwith a generally flat shape.

The invention also proposes an electronic appliance having such acasing.

Such protective casings are for example used for mobile telephones ofthe GSM type.

The protective casing naturally protects the components of theelectronic appliance such as a keypad and switches whose activationmodifies the electrical state of a control circuit. In the case of amobile telephone, the protective casing must in particular also protecta display screen which provides the interface between the appliance andthe user.

To do this, the casing generally has an opening or window closed off bya body made from transparent material with a generally flat shape. Thedisplay screen is then arranged inside the casing opposite the opening.

In some cases, the body made from transparent material has specialoptical properties such as a magnifying effect which then improves thelegibility of the information displayed on the display screen.

The body made from transparent material must be sufficiently strong toprotect the display screen against impacts or scratches which may be dueto rubbing of the electronic appliance against other objects, forexample metallic keys, when it is placed inside a purse.

Thus the dimensions of the body made from transparent material, inparticular its thickness, as well as its characteristics, in particularthe hardness of its external face, are determined so as to resistimpacts and scratches.

To do this, it is known that a body made from plastics material can beused, whose thickness is around 2 to 5 mm and whose external face iscovered with an anti-scratch protective cladding which increases thesurface hardness of the external face of the body.

The fixing of the transparent body to the casing is generally carriedout by adhesive bonding of a peripheral area of the transparent body,which is oriented towards the inside of the casing, on a peripheral areaof the opening which is advantageously situated inside the casing sothat the external face of the casing and the external face of thetransparent body are substantially aligned or flush.

In this case, glue is visible from the outside of the casing through theplastic body. This is detrimental to the aesthetic appearance of thetelephone.

So as to conceal the glue, a decorative cladding can be placed on theexternal face of the body made from transparent material before thisface is covered with the protective cladding.

However, when the protective cladding is not sufficiently strong toprotect the body made from transparent material, the decorative claddingmay be scratched.

The distance which separates the display screen and the decorativecladding, which is around several millimeters, causes an impression ofdistancing of the screen towards the inside of the casing. Thisimpression is detrimental to the overall appearance of the electronicappliance.

In addition, when light external to the casing illuminates the latter ina direction which is not perpendicular to the overall plane of the bodymade from transparent material, the protective cladding causes theformation of shadows on the screen, which interfere with the reading ofthe information supplied by the screen.

To remedy these problems, it is known that the decorative cladding canbe interposed between the fixing area of the transparent body and thefixing glue.

However, it is not possible to concomitantly place the protectivecladding and the decorative cladding on their respective areas situatedon opposite faces of the transparent screen.

So that the decorative cladding provides a positive aesthetic effect, itmust be placed on a flat surface. However, the surface evenness of theinternal face of the transparent body is not always sufficient. Thiscauses irregularities in the cladding which are visible to the user.

When the thickness of the transparent body is around a few millimeters,the user can see through the side faces of the body, which isdetrimental to the overall appearance of the electronic appliance.

In order to resolve these problems, the invention proposes a protectivecasing for an electronic appliance of the type which has a shell inwhich there is produced an opening closed off by a body made fromtransparent material with a generally flat shape, of the type in whichat least one internal peripheral annular area for fixing the transparentbody is fixed to an area opposite the periphery of the opening by fixingand/or positioning means with the interposing of a first decorativecladding between the peripheral area for fixing the transparent body andthe fixing and/or positioning means, characterized in that theperipheral fixing area is inclined with respect to the overall plane ofthe transparent body.

According to other characteristics of the invention:

the inclined peripheral fixing area extends over the whole of theperiphery of the transparent body;

the substantially flat external face of the transparent body is coatedat least partially with a second cladding, notably a protectivecladding, for example non-scratch, for the external face of thetransparent body;

the fixing and/or positioning means include a layer of glue;

the fixing and/or positioning means include at least one insert, and thefirst cladding at least partially masks the insert;

the angle of inclination of the peripheral fixing area is around 30°with respect to the overall plane of the transparent body.

The invention also proposes a method of manufacturing a protectivecasing of the type described previously, characterized in that: theinsert is produced by molding a first material in a first cavitydelimited by the impressions of two matrices of a first mold; then theinsert is transferred into a second cavity, delimited by the impressionsof two matrices of a second mold, into which a second transparentmaterial is injected so as to produce the transparent body by moldingthe second material on the insert.

According to other characteristics of the method:

when the insert is being produced, the first decorative cladding isdeposited on the area of the insert complementary to the peripheralfixing area of the transparent body, by transferring the firstdecorative cladding which belongs to a film which extends in the cavityof the first mold;

when the transparent body is molded, the second cladding is deposited onat least part of the external face of the body by transfer of the secondcladding which belongs to a film which extends in the cavity of thesecond mold.

The invention also proposes a tool for manufacturing a protective casingof the type which has:

a first mold consisting of a first bottom matrix and a first top matrixeach having an impression so as to delimit a first cavity in which theinsert is produced, and

a second mold consisting of a second bottom matrix and a second topmatrix each having an impression so as to delimit a second cavity intowhich the insert on which the transparent body is molded is transferred,characterized in that the first bottom matrix and the second bottommatrix each have an identical impression.

According to other characteristics of the tool:

the first and second bottom matrices are able to move with respect tothe first and second top matrices;

the first and second top matrices are produced as a common top matrixhaving two impressions, the first and second bottom matrices areproduced as a common bottom matrix having two impressions and in that acommon matrix is mounted so as to pivot about an axis orthogonal to theparting plane of the molds so that its pivoting through 180° allows thealternating cooperation of each of these two impressions with each ofthe impressions of the other two matrices.

The invention will be further described with reference to examples ofembodiment shown in the drawings to which however the invention is notrestricted:

FIG. 1 is a schematic view in transverse section of a protective casingaccording to a first embodiment of the state of the art;

FIG. 2 depicts to a large scale a detail of the previous figure;

FIG. 3 is a view in transverse section of a protective casing accordingto a second embodiment of the state of the art;

FIG. 4 depicts to a large scale a detail of the previous figure;

FIG. 5 is a view in transverse section of a protective casing accordingto a first embodiment of the invention;

FIG. 6 depicts to a large scale a detail of the previous figure;

FIG. 7 is a view in transverse section to a larger scale of part of aprotective casing according to a second embodiment of the invention;

FIG. 8 is a schematic perspective view of a tool for manufacturing aprotective casing according to the invention;

FIGS. 9A to 9F are views in section of the tool depicted in the previousfigure which illustrates the successive steps of the method ofmanufacturing the protective casing produced according to the invention.

In the following description the identical or similar elements will bedesignated by the same reference figures. A terminology horizontal,vertical, top and bottom will be adapted, non-limitatively, withreference to the figures.

FIGS. 1 to 4 depict two examples of embodiment according to the state ofthe art of an electronic appliance 10, which is here for example amobile telephone of the GSM type. The telephone 10 has a protectivecasing 12 in which there are arranged the components which enable thetelephone to function. Amongst these elements only a display screen 14is shown.

So as to facilitate an understanding of the description, an internal andexternal orientation will be used with respect to the inside and outsideof the protective casing 12, respectively.

To facilitate the assembly of the components, the protective casing 12has a bottom shell 16 and a top shell 18 which are distinct. Thus theelements are mounted therein since the two shells are connected togetherso as to close the casing 12.

The top shell 18 has an opening or window 20 which is closed off by abody made from transparent material 22 with a generally flat shape. Theopening 20 is produced in the substantially horizontally oriented frontor main face 23 of the telephone 10.

So as to provide the esthetic unity of the telephone 10, the externalface 24 of the body made from transparent material 22 is in line withthe external face 26 of the top shell 18.

The periphery of the opening 20 has a stepped rim 28 which extendsinside the casing 12 and which receives the body made from transparentmaterial 22.

The fixing of the body 22 to the top shell 18 is obtained by fixingmeans 34.

Here the fixing of the body 22 on the shell 18 is obtained by gluing theinternal and bottom peripheral annular fixing area 30 of the body 22 toa facing top area 32 of the rim 28 of the periphery of the opening 20.

Thus a layer of glue 35 is deposited between the annular area 30 of thebody made from transparent material 22 and the fixing area 32 of the topshell 18.

So as to mask the fixing means 34, a peripheral annular area 36 of theexternal face 24 of the body 22 is covered with a first decorativecladding 38. Thus, when the user looks at the main face 23 of thetelephone 10, the first decorative cladding 38 masks the rim 28 and thelayer of glue 35.

However, such a design has drawbacks already cited.

These are in particular the impression of distancing of the screen 14towards the inside of the casing 12 and the formation of shadows on thedisplay screen 14.

This is because, when the light external to the casing 12 illuminatesthe latter in a direction which is not perpendicular to the overallplane of the main face 23 of the casing 12, notably to the external face24 of the body 22 made from transparent material, the decorativecladding 38 forms shadows on the screen which interfere with the readingof the information which it supplies.

FIG. 2 shows this phenomenon. A light source 39 emits a beam of light 40which is inclined with respect to the external face 24 of the body 22.Some of the light beam 40 is blocked by the decorative cladding 38 and ashadow area 42 is formed on the display screen 14 of the telephone.

According to a second example of embodiment, it is also known, inaccordance with FIGS. 3 and 4, that the first decorative cladding 38covers a peripheral area 50 of the internal bottom face 52 of the body22.

Thus the layer of glue 35 which is interposed between the firstdecorative cladding 38 and the rim 28 is not visible from the outside ofthe telephone 10.

However, when the body 22 is thick, the user can “see” through itslateral faces 54, which is detrimental to the esthetic appearance of thetelephone 12.

In addition, the distance between the external face 24 of the body 22and the first decorative cladding 38 gives an impression of distancingof the first decorative cladding 38 and of the display screen 12, whichis detrimental to the overall appearance of the telephone 10.

It is therefore preferable to limit the thickness of the body 22.

However, a reduction in the thickness does not enable the body towithstand all the impacts to which it may be subjected. Consequently itis necessary to find a compromise which makes it possible to preservethe esthetic appearance of the telephone 10 and which enables the body22 to resist impacts to the maximum possible extent.

So as to provide a solution to these problems, the invention proposesthat the peripheral fixing area 30 be inclined with respect to theoverall plane of the transparent body 22, notably with respect to itsexternal face 24.

The angle ∝ of inclination of the peripheral fixing area 30 with respectto the substantially horizontal overall plane of the transparent body 22can for example be between 15 and 30 degrees.

Thus, whatever the thickness of the body 22 made from transparentmaterial, the inclined peripheral fixing area 30 eliminates theimpression of depth of the display screen 14 inside the casing 12.

According to a first embodiment of the invention depicted in FIGS. 5 and6, the rim 28 of the top shell 18 is inclined by an angle ∝ identical tothat of the peripheral fixing area 30.

In accordance with the state of the art, the body 22 made fromtransparent material is fixed to the top shell 18 by fixing means 34which include for example a layer of glue 35 with the interposing of afirst decorative cladding 38 so as to mask the layer of glue 35 from theoutside.

Advantageously, the inclined peripheral fixing area 30 is annular andextends over the entire periphery, for example rectangular with roundedcorners, of the body 22 made from transparent material. This ensure theesthetic unity of the body 22 and of the telephone 10.

The first decorative cladding 38 extends substantially from the externalface 26 of the top shell 18 as far as the display screen 14 so as togive an impression of continuity between the main face 23 of thetelephone 10 and the display screen 14, which improves the estheticappearance of the telephone 10.

In addition, as can be seen by comparing FIGS. 4 and 6, the side faces54 of the body 22 are very small. Thus the user of the appliance cannotsee the rim 28 of the top part of the shell 18 through the body 22. Thisimproves the esthetic appearance of the telephone 10 still further.

Advantageously, according to a variant which is not shown, theperipheral fixing area 30 extends from the internal face 52 as far asthe external face 24 of the body 22 so as to eliminate the side faces 54and reinforce the impression of continuity between the main face of thetelephone 10 and the display screen 14.

Such a design eliminates any risk of formation of shadows on the displayscreen 14, whatever the angle of incidence of the light with respect tothe main face 23 of the telephone 10.

In addition, the first decorative cladding 38 being situated between thebody 22 made from transparent material and the rim 28 of the top shell18, it is perfectly protected and under no circumstances is there a riskof being damaged by external attacks such as rubbing of the main face 23against other objects.

The external face 24 of the body 22 can be covered with a secondcladding 55 (FIG. 7).

The second cladding 55 can be a non-scratch cladding which protects theexternal face against any scratches which may be caused by the telephone10 rubbing on other objects.

So as to facilitate the display of information on the screen 14 underall circumstances, whatever the angle of incidence of the light withrespect to the external face 24 of the body 22, the second cladding 55can be a non-reflective cladding.

FIG. 7 depicts a second preferred embodiment of the invention.

The protective casing 12 consists of a transparent body 22 whose meansof fixing 34 with the top shell 18 include an insert 56 which isadvantageously of annular shape.

The insert has a shape complementary to that of the stepped rim 28. Itis delimited by a horizontal bottom face 57 which is in abutment on thearea 32 of the rim 28, and by a top face 59 inclined by the angle ∝ inaccordance with the invention. The insert 56 is thus interposedvertically between the rim 28 and the screen 22.

The insert 56 is masked towards the outside by the first decorativecladding 38 which extends opposite its inclined top face 59.

The insert 56 has studs 58 which extend substantially vertically towardsthe inside of the casing 12 and which cooperate with orifices 60produced in the rim 28 of the top shell 18.

The studs 58 make it possible to position and fix the body 22 withrespect to the top shell 18.

The studs 58 can be glued inside the orifices 60 so as to fix the body22 to the top shell 18.

According to a variant, the studs 58 can be forcibly engaged in theorifices 60, or crimped hot.

The invention also proposes a tool 70 for manufacturing the protectivecasing 12 according to the second embodiment, with insert, of theinvention. The tool 70 in particular makes it possible to effect themolding of the insert 56 and the overmolding of the body 22 made fromtransparent material, with the interposing of the first cladding 38.

The tool 70 depicted in FIGS. 8 and 9A to 9F includes two molds.

In accordance in particular with FIGS. 8, 9A and 9B, a first mold M1consists of a first bottom matrix 74 and a first top matrix 76 eachhaving an impression 78 and 80 respectively, so as to delimit a firstcavity 82 in which the insert 56 is produced by molding.

The first mold M1 is then designated in the figures by the referenceM1(X,Y) in which X and Y correspond to the reference of thecorresponding top and bottom matrices respectively.

In accordance in particular with FIGS. 8, 9A and 9B, a second mold M2consists of a second bottom matrix 86 and a second top matrix 88 eachhaving an impression 90, 92 respectively so as to delimit a secondcavity 94 into which the insert 56 is transferred and on which thetransparent body 22 is molded.

In a similar fashion to the first mold M1, the second mold M2 is thendesignated in the figures by the reference M2(X, Y) in which X and Ycorrespond to the reference of the corresponding top and bottom matricesrespectively.

In accordance with the invention, the first bottom matrix 74 and thesecond bottom matrix 86 each have identical impressions 78 and 90.

In addition, the first and second bottom matrices 74 and 86 are able tomove with respect to the first and second top matrices 76 and 88.

Advantageously, in accordance with FIGS. 8 and 9A to 9F the first andsecond top matrices 76 and 88 are produced in the form of a common topmatrix 96 having two impressions 80 and 92. Likewise the first andsecond bottom matrices 74 and 86 are produced in the form of a commonbottom matrix 98 including the two impressions 78 and 90.

The common top matrix 96 is mounted so as to pivot about a vertical axisA orthogonal to the horizontal parting line P of the molds so that itspivoting through 180° allows the alternating cooperation of each of thetwo impressions 80 and 92 with each of the two impressions 78 and 90 inthe other two matrices 74 and 86 respectively.

The use of the tool 70 will be explained by the description of themethod of manufacturing the protective casing 12 according to the secondembodiment.

According to this method, the insert 56 is produced by molding from afirst material in a first cavity 82, delimited by the impressions 78 and80 in the two matrices 74 and 76 of the first mold M1.

At the start of the production process, the first and second cavities 82and 94 in the first and second molds M1 and M2 are empty in accordancewith FIG. 9A. In accordance with FIG. 9B, a first plastics material isinjected into the first cavity 82 through the channels 100 which passthrough the first bottom matrix 74 so as to produce the insert 56.

Advantageously, when the insert 56 is produced, the first decorativecladding 38 is deposited on the area of the insert associated with theperipheral fixing area 30 of the transparent body 22.

The deposition of the first cladding 38 is produced by transfer using afilm 102 which extends in the cavity 82 of the first mold M1.

The film 102 can be made from heat-resistant plastic. The first cladding38 is deposited on the face of the film 102 which is oriented downwardstowards the first bottom matrix 74 when the insert 56 is produced.

The adhesion between the first cladding 38 and the film 102 is suchthat, when the first hot plastics material is injected into the firstcavity 82, the heat causes the detachment of the first cladding 38 fromthe film 102. Thus the first cladding 38 is “deposited” on the part ofthe insert 56 with which it is in contact.

Next the common top matrix 96 is shifted upwards so as to open the moldsM1 and M2 and then pivots through 180° about the axis A, in accordancewith FIG. 9C.

The first mold M1 then consists of the first bottom matrix 74 and thesecond top matrix 88 and the second mold M2 consists of the secondbottom matrix 86 and the first top matrix 76.

The film 102 is translated horizontally so that the first decorativecladding 38 is opposite the impression 80 in the first top matrix 76,and so that a second cladding 55, for example the non-scratch protectivecladding 55, is opposite the impression 92 in the second top matrix 88.

The common top matrix 96 is then shifted downwards so as to close themolds M1 and M2.

The first top matrix 76 is then opposite the second bottom matrix 86 soas to form the first cavity 82, and the second top matrix 88 is oppositethe first bottom matrix 74 so as to form the second cavity 94, inaccordance with FIG. 9D.

When the molds M1 and M2 are closed, the first plastics material isinjected through the channels 100 in the second bottom matrix 86 intothe first cavity 82 so as to produce the insert 56.

Concomitantly, transparent plastics material is injected through thecentral channel 104 in the first bottom matrix 74 into the second cavity94 so as to mold the body 22 made from transparent material onto theinsert 56 produced at the previous step. During this step, thedecorative 38 and protective claddings deposited on the film 102 aretransferred onto corresponding areas of the insert 56 and of the body 22respectively.

Thus the method makes it possible to produce concomitantly an insert 56and to mold the body 22 onto an insert 56 produced at the previous step.

FIG. 9E depicts the opening in the first and second molds M1 and M2, andthe ejection of the body 22 molded onto the insert 56.

Next, in accordance with FIG. 9F, the common top matrix 96 once againpivots through 180° into a position identical to that depicted in FIG.9A.

The method continues, thus making it possible, each time the molds M1and M2 are opened, to produce an insert 56 and to mold a body 22 ontothe insert 56 already produced.

So as to easily translate the film 102 each time the molds M1 and M2 areopened, it can be wound on two reels, not shown, situated on each sideof the tool 70.

One of them, by unwinding, supplies the tool 70 with claddings. Theother stores the film 102 by rewinding it.

What is claimed is:
 1. A protective casing (12) for an electronicappliance (10) of the type which has a shell (18) in which there isproduced an opening (20) closed off by a body (22) made of transparentmaterial with a general flat shape, of the type in which at least oneinternal peripheral annular area (30) for fixing the transparent body(22) is fixed to an opposite area (32) of the periphery of the opening(20) by fixing and/or positioning means (34) with the interposing of afirst decorative cladding (38) between the peripheral area (30) forfixing the transparent body (22) and the fixing and/or positioning means(34), characterized in that the peripheral fixing area (30) is inclinedwith respect to the overall plane of the transparent body (22).
 2. Aprotective casing (12) as claimed in claim 1, characterized in that theinclined peripheral fixing area (30) extends over the entire peripheryof the transparent body (22).
 3. A protective casing (12) as claimed inclaim 1, characterized in that the substantially flat external face (24)of the transparent body (22) is at least partially clad with a secondcladding (55), notably a protective cladding, for example non-scratch,for the external face (24) of the transparent body (22).
 4. A protectivecasing (12) as claimed in claim 1, characterized in that the fixingand/or positioning means (34) include a layer of glue (35).
 5. Aprotective casing (12) as claimed in claim 1, characterized in that thefixing and/or positioning means (34) include at least one insert (56),and in that the first cladding (38) at least partially masks the insert(56).
 6. A protective casing (12) as claimed in claim 1, characterizedin that the angle of inclination of the peripheral fixing area (30) isaround 30° with respect to the overall plane of the transparent body(22).
 7. An electronic appliance having a casing as claimed in claim 1.8. A protective casing (12) for an electronic appliance (10),comprising: a bottom shell (16); a top shell (18) including an opening(20) and a fixing area (32) adjacent said opening (20); a display screen(14) disposed between said bottom shell (16) and said top shell (18),said display screen (14) viewable through said opening (20); atransparent body (22) including a surface area (30) inclined withrespect to an overall plane of said transparent body (22), said surfacearea (30) being affixed to said fixing area (32) to close said opening(20); an insert (56) affixing said inclined surface area (30) to saidfixing area (32), said insert (56) being inclined with respect to anoverall plane of said fixing area (32), wherein said fixing area (32)includes an orifice (60), and said insert (56) includes a stud extendingthrough said orifice (60); and a decorative cladding (38) disposedbetween said inclined surface area (30) and said insert (56).
 9. Theprotective casing (12) as claimed in claim 8, wherein said inclinedsurface area (30) extends over an entire periphery of said transparentbody (22).